Non-irritating, non-blurring ophthalmic sunscreen

ABSTRACT

A non-irritation, non-blurring ophthalmic sunscreen composition contains a liquid vehicle base, such as an artificial tear formulation or an ophthalmic suspension or ointment. The composition includes at least one inorganic and/or at least one organic active ingredient. The inorganic active ingredients may include, but not be limited to zinc oxide, titanium dioxide, iron oxide, zirconium oxide, and cerium oxide. The organic active ingredients may include, but not be limited to dioxybenzone, octinoxate, octisalate, homosalate, avobenzone, octocrylene, para-aminobenzoic acid, cinoxate, methyl anthranilate, octocrylene, padimate O, ensulizole, sulisobenzone, trolamine salicylate, and ecamsule.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 14/715,894, filed on May 19, 2015, which claims priority toprovisional application 62/000,071 filed on May 19, 2014, each of whichare hereby incorporated by reference.

DESCRIPTION Field of the Invention

The present invention generally relates to a sunscreen formulationdesigned for protecting the eyes including the conjunctiva, cornea,lens, and retina. More particularly, the present invention relates to anon-irritating sunscreen that is applied directly onto the ocularsurface of the eye for protection from ultraviolet radiation.

Background of the Invention

Ultraviolet radiation is part of the electromagnetic spectrum thatreaches the earth from the sun. It has wavelengths shorter than visiblelight, making it invisible to the naked eye. These wavelengths areclassified as UVA, UVB, or UVC. UVA has the longest of the three at320-400 nanometers. UVA is further divided into two wave ranges, UVA I,which measures 340-400 nanometers (nm, or billionths of a meter), andUVA II which extends from 320-340 nanometers. UVB ranges from 290 to 320nm. With even shorter rays, most UVC is fortunately absorbed by theozone layer and does not reach the earth.

Both UVA and UVB penetrate the Earth's atmosphere and play an importantrole in conditions such as premature skin aging, eye damage, hairdamage, and certain skin cancers.

Photoconjunctivitis and Photokeratitis describe conditions whereultraviolet radiation inflames and/or damages the delicate structures ofthe ocular surface (the conjunctiva and the cornea, respectively). UVexposure to the eyes (either direct or indirect) can cause severeredness, dryness, irritation, tearing, photosensitivity, and pain. Thispain can be so severe as to cause chemosis and sloughing of the cornealepithelium with resultant scarring and even permanent vision loss.

Long-term ophthalmic exposure to UV radiation has been associated withpermanent thickening of the conjunctiva (called a pingueculum), vascularproliferation and tissue growth over the cornea (called a pterygium),conjunctival discoloration (melanosis), even cancer (e.g.,conjunctival/uveal melanoma).

Long-standing UV exposure to the eyes has also been associated withdamage to the internal structures of the eyes, e.g., the natural lensand the retina. Certain forms of cataracts (e.g., nuclear sclerosis), aswell as macular degeneration have been linked to the damage caused byoxidative damage from UV exposure.

Accordingly, protecting the ocular structures form UV radiation may bebeneficial in preventing such oxidative damage that leads to all ofthese very common ophthalmic conditions. Until recently, the onlyproposed mechanism to protect the eyes from UV radiation has been theuse of glasses with UV protection, sunglasses, and tinted contactlenses.

There is a plethora of prior art suggesting the use of differentphysical and/or chemical sunscreen compositions for just that skin andformulations that don't damage the eye should any formulation get withinthe eye, but these patents and prior art did not envision and/ordescribe the use of such formulations for protecting the ocularstructures in any way. For example, Dueva-Koganov et al. (Pub. No.: US2010/0226867 A1) proposed a “cosmetic and/or dermatological” compositionthat are non-irritating to mammalian eyes. While this is a significantadvantage for a dermatological composition not to burn the eyes in caseof inadvertent contact, it does not describe the application of asolution that is designed for “ophthalmic” use per se.

There have been inventions that have proposed formulations specificallyfor the purpose of protecting the human eye from UV radiation, but suchprior art has suggested formulations that are very different than whatis proposed herein with potential side-effects that may render themimpractical for frequent use. Such prior art has proposed compositionsthat would make vision extremely blurry and/or be extremely irritatingto the eyes, thus making them less suitable for frequent use by thegeneral population.

For example Michalos (U.S. Pat. No. 4,923,693) proposed the use of0.3-0.4% hydroxypropylmethylcellulose in the form of an eyedrop orointment applied to the eyes prior to exposure to UV radiation). Thisformulation, while effective against UV radiation, would affect visiontremendously and make it difficult for the user to see clearly forhours.

Baron (U.S. Pat. No. 5,041,244) described an ophthalmic liquid sunglassthat is composed of dosages of chromophores in aqueous gel to blocktransmission of all or various spectrums of UV from the eyes. He hasdescribed the use of high molecular weight polymers which form viscousdispersions and can be used to prolong the curation of the chromophorewhen the gel is applied to the eye. This alone would cause significantblurring of the users' vision. Further, there is no mention of theirritation that's caused once this mixture is directly applied to theeye. This makes Baron's invention not entirely practical for frequentuse by the public.

This present disclosure describes the composition of a sunscreensolution, suspension, emulsion, and/or an ointment that is designed tobe directly applied to the eye itself to protect it from UV damagewithout causing significant irritation to the eye or affecting theusers' vision. The present invention fulfills these needs for a new formof UV radiation protection and provides other related advantages.

SUMMARY OF THE INVENTION

Advances in our understanding of the sun protective effects of organicand inorganic ingredients has lead to the development of sunscreenpreparations with very effective protection against the ultraviolet raysof the sun. Until now, the effects of these ingredients has only beendescribed for the skin, and the prior art has warned against the use ofsuch ingredients on the ocular surface. In fact, people are asked torinse their eyes thoroughly in case such ingredients get into theireyes. The present invention describes the specific use of suchingredients onto the ocular surface itself. The present inventionproposes formulations that provide very high SPF for the eyes, whilecausing minimal irritation without making vision blurry.

Examples of embodiments of the present invention include compositionsthat are manufactured as ophthalmic solutions, emollients, creams, orointments that can be instilled directly on the eyes. It is understoodthat the use of the term “ophthalmic solution” shall include emollients,creams and ointments that can be instilled directly on the eyes.

An embodiment of the present invention includes an ophthalmic solutioncomprised of diluted forms of an inorganic active ingredient such astitanium dioxide, zinc oxide, iron oxide, zirconium oxide, cerium oxide,or mixtures thereof. This composition may also contain a weakconcentration of an organic active ingredient such as avobenzone,octinoxate, octisalate, homosalate, octocrylene, para-aminobenzoic acid,cinoxate, dioxybenzone, methyl anthranilate, octocrylene, padimate O,ensulizole, sulisobenzone, trolamine salicylate, ecamsule, and mixturesthereof.

An example embodiment of the present invention includes an ophthalmicsunscreen composition which is comprised of anywhere from 0.25% to up to15% zinc oxide by weight.

Another example of this invention includes embodiments comprised ofoctinoxate and/or octisalate.

Another example of this invention includes embodiments comprised of anemulsifier, silicone- or acrylic-based, glycosides, polyethyleneglycols, or a mixture thereof.

Another example of this invention includes embodiments comprised ofsunscreen composition comprising an emulsifier selected from the groupconsisting of Arlacel P 135, DC 9011 silicone elastomer, Abil WE 09,Abil EM-90, Emulgade 68/50, Simulgel A, Simulgel EG, and mixturesthereof.

Another example of this invention includes embodiments comprised of anemollient. Said emollient may be selected from the group consisting ofAloe extracts, ethers, oleaginous esters, and mixtures thereof.

Another example of this invention includes embodiments comprised of anemollient selected from the group consisting of actiphyte of aloe vera,Cetiol OE, Lexol IPL, octyl palmitate, neopentyl glycol heptanoate,neopentyl glycol diheptanoate, Trivent NP-13, CJ2- is alkyl benzoate,and mixtures thereof.

Other features and advantages of the present invention will becomeapparent from the following more detailed description, when taken inconjunction with the accompanying drawings, which illustrate, by way ofexample, the principles of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Examples of ophthalmic sunscreen compositions of the present inventionprovide an SPF of up to 50 or higher. As the eyes are usually not indirect exposure to UV radiation as opposed to the skin, such high SPFratings may not be necessary for the present invention, and as such, theconcentration of the active (and inactive) ingredients may be much lowerthan those proposed for dermal use.

The application of much lower concentrations of these ingredients willlead to much lower incidences of ophthalmic irritation/stinging whenapplied, and will lessen the known side-effects of such ingredients.Further, by reducing the concentrations of these ingredients, possibleabsorption of these ingredients into the eye (i.e., through the Cornea)will be reduced as to prevent possible intra-ocular effects (e.g.,cataract formation).

Compositions of the present invention are now described, but are notlimited to these embodiments.

Ophthalmic sunscreen compositions according to the present invention maycontain a liquid vehicle base, such as an artificial tear formulation,which may be water and/or oil-based, or an ophthalmic suspension orointment and include at least one inorganic and at least one organicactive ingredient.

Inorganic active ingredients may include, but not be limited to zincoxide, titanium dioxide, iron oxide, zirconium oxide, and cerium oxide,optionally in micronized form as to prevent blurred vision when applied.

Organic active ingredients may include, but not be limited todioxybenzone, octinoxate, octisalate, homosalate, avobenzone,octocrylene, para-aminobenzoic acid, cinoxate, methyl anthranilate,octocrylene, padimate O, ensulizole, sulisobenzone, trolaminesalicylate, and ecamsule.

The inactive ingredients of the present invention shall also includeemulsifier(s) and/or emollient(s). Silicone-based emulsifiers likepolyethylene glycols, polysiloxanes, glycosides are excellent choices.Acrylic-based emulsifiers, and mixtures thereof may also be used safelyfor the present preparation. Emollients may include, but not be limitedto aloe extracts, oleaginous esters, and ethers, or a combinationthereof.

The composition of the present invention shall also include, but not belimited to preservatives, chelating agents, and/or antioxidants.

The following examples describe a composition of the present invention,but it is obviously not intended to limit the scope of the invention.

Example 1

An ophthalmic sunscreen solution can be synthesized by mixing 5%micronized zinc oxide and 3% octinoxate in an ophthalmic artificial tearformulation. This solution may contain carboxymethylcellulose sodium0.1%; glycerin 0.25%; boric acid; calcium chloride dihydrate;erythritol; levocarnitine; magnesium chloride hexahydrate; potassiumchloride; purified water; sodium borate decahydrate; and sodium citratedihydrate.

Example 2

An ophthalmic sunscreen solution can be synthesized by mixing a range of5% micronized titanium dioxide and 3% octisalate in an ophthalmicartificial tear solution.

Example 3

An ophthalmic sunscreen ointment can be synthesized by mixing a range of5% micronized zinc oxide and 3% octinoxate in an ophthalmic ointmentconsisting of hypromellose

, boric acid, sodium perborate, phosphonic acid, potassium chloride,purified water, and sodium chloride.

Although several embodiments have been described in detail for purposesof illustration, various modifications may be made to each withoutdeparting from the scope and spirit of the invention. Accordingly, theinvention is not to be limited, except as by the appended claims.

What is claimed is:
 1. A method of protecting a subject's eyes fromsunlight, comprising: applying an ophthalmic sunscreen solution directlyonto the ocular surface of the subject's eyes, wherein the ophthalmicsunscreen solution consists of an active sunscreen component and aninactive liquid vehicle base wherein the active sunscreen componentconsists of: 0.25 percent to 15 percent by weight of an inorganic activeingredient, selected from the group consisting of titanium dioxide, zincoxide, iron oxide, zirconium oxide, cerium oxide and mixtures thereof;and 0.25 percent to 15 percent by weight of an organic activeingredient, selected from the group consisting of dioxybenzone,octisalate, homosalate, avobenzone, octocrylene, para-aminobenzoic acid,cinoxate, methyl anthranilate, 2-ethylhexyl 4-(dimethylamino)benzoate,ensulizole, sulisobenzone, trolamine salicylate and ecamsule; andwherein the inactive liquid vehicle base is an ophthalmic artificialtear formulation.
 2. The method of claim 1, wherein the inactive liquidvehicle base comprises an emulsifier.
 3. The method of claim 2, whereinthe emulsifier is selected from the group consisting of a silicone-basedemulsifier, a polyethylene glycol emulsifier, a polysiloxane emulsifier,a glyscoside emulsifier, an acrylic-based emulsifier and combinationsthereof.
 4. The method of claim 1, wherein the inactive liquid vehiclebase comprises an emollient.
 5. The method of claim 4, wherein theemollient is selected from the group consisting of aloe extracts,oleaginous esters, ethers and combinations thereof.
 6. The method ofclaim 1, wherein the inactive liquid vehicle base comprises a chelatingagent.
 7. The method of claim 1, wherein the inactive liquid vehiclebase comprises a preservative, a chelating agent, an antioxidant, anophthalmic lubricant, an ophthalmic astringent or ecamsule.
 8. Themethod of claim 1, wherein the ophthalmic sunscreen solution is in theform of an eye drop, a suspension, an emulsion, or an ointment.